81805264 has 20 divisors (see below), whose sum is σ = 162185056. Its totient is φ = 39951072.

The previous prime is 81805237. The next prime is 81805267. The reversal of 81805264 is 46250818.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81805267) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 58764 + ... + 60139.

Almost surely, 2^81805264 is an apocalyptic number.

It is an amenable number.

81805264 is a deficient number, since it is larger than the sum of its proper divisors (80379792).

81805264 is a wasteful number, since it uses less digits than its factorization.

81805264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118954 (or 118948 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 34.

The square root of 81805264 is about 9044.6262498790. The cubic root of 81805264 is about 434.1039625790.

The spelling of 81805264 in words is "eighty-one million, eight hundred five thousand, two hundred sixty-four".